Measuring technology for flow rate, mass flow rate and flow velocity

Energy management DIN EN ISO 50001/ measurement of compressed air consumption

Measuring standard flow rate in compressed air pipes


process data

measuring task:
standard flow rate; mass flow rate

measuring point
in compressed air pipe

measuring range:
0.04 to 20,000 Nm³/h

maximum working pressure:
16 bar

process environment
optional up to zone 0


Generating compressed air is highly energy costly. Companies are constantly trying to reduce consumption. Consumption measurement ist also necessary for a possible DIN EN ISO 50001 certification for energy management.

Therefore measurement of compressed air consumption has been a standard procedure in the industry for years now. The source (the compressor), certain parts of the company from production halls to individual production cells are necessary to be monitored.

Portable temporary measurements are also required. That way consumption can be measured at a specific point of the compressed air net and certain actions can be taken. The goal is to increase energy efficiency and therefore optimise the company’s ecobalance.

Flow rate of compressed air can vary a lot depending on the location of measuring. Applied sensors should therefore have a great turndown ratio.

your advantage

many areas of application
very high turndown ratio of 1:1000

negligible pressure loss compared to other measuring methods

versions for ATEX zone 1 and 0 are available

Recommended products

Thermal probe TA 10 ZG2d
Standard compact sensor

To the product Product data sheet

Thermal measuring tube TA Di
Standard – with an integrated transducer

To the product Product data sheet

Does compressed air have to be so expensive?

No way!

Compressed air is an expensive energy source and should therefore be used responsibly. To recognise possible savings, measuring instruments for precise measurement of compressed air consumption is required, improving energy balance and saving costs. Compressed air is also needed on a large scale in municipal sewage treatment plants for their aeration basins. The demand represents a significant if not the largest share in the energy consumption of the municipality providing great potential for savings. Compressed air and electricity consumption can be localized and reduced through an exact consumption measurement. This is an essential contribution to the company’s energy management and can be part of the certification.

What advantages do thermal flow sensors provide for energy management?

Höntzsch’s thermal flow sensor TA allows a direct gas mass flow rate measurement without additionally requiring pressure and temeprature sensors. It is very small and therefore not posing a big obstruction in the pipeline making the pressure loss quite negligible. The small time constant of 1 s enables an accurate measurement with high temporal resolution. Our thermal sensor TA is suited for pipelines with an inside diameter starting at 8 mm.

Additionally to compressed air other gases such as propane, butane or hydrogen can be measured as well. They are also very valuable gases, their consumption a cost relevant factor and are important for the energy management.

data transfer for consumption measurement of compressed air

Measuring data is usually transmitted via the power interface (4 … 20 mA). M-Bus interface is also available as well as transmitting data via WIFI.     

For transmitting quantity pulse or limit value there’s also a digital outlet available. 

Mobile consumption measurement

Flowtherm NT.2 is used with a mobile sensor for short-term measurements and can display and store values. Series of measurement is also possible.     

All measured data can be send to a computer for further data processing.


Höntzsch TA sensors have no moving parts and ensure high long-term measurement accuracy. The sensor is made out of stainless steel and therefore easy to clean. It is also available with a display and keypad allowing direct parameter setting in the sensor.        

The ATEX-version of our TA sensors for zone 1 (zone 0) and category 2 (zone 1) can be used for measurements in potentially explosive areas. The mobile use in category 2 (zone 1) is also possible with a Höntzsch handheld unit.

Analog to consumption measurement of compressed air our flow sensor TA can also be used for the measuring of natural gas or clean gas. Calibration with the actually used gas is possible in the Höntzsch calibration laboratory.